Abrasive article



1943- w. s. HOSKl N ETAL v 2,309,456

ABRASIVE ARTI CLE Filed Feb. 16, 1942 INVENTORS WILLIAM $.HOSKIN FRANK B.WOLF$CHLA ER BY. 7 I 2 Z I ATTORNEYS Patented Jan. 26, 1943 ABRASIVE ARTICLE William S. Hoskin, Highland Park, and Frank B.

Wolfschlager, Holly, Micln, assignors to Mid- West Abrasive Company, Detroit, Mich, a corporation of- Delaware Application February 16, 1942, Serial No. 481,150

13 Claims.

The present invention relates to an abrasive article and more particularly to an abrasive article formed of flexible, abrasive strip material coiled into helical convolutions.

It is an object of the present invention to provide an improved abrasive article in the form of; abrasive strip material coiled into helical convolutions.

It is a further object of the invention to provide an improved abrasive article in the form of a belt or endless rope of flexible, abrasive strip material coiled into helical convolutions.

Another object of the invention is to provide an improved abrasive tool in the form of a mandrel having flexible, abrasive strip material formedinto helical convolutions surrounding said mandrel and having one end of the strip material anchored to the mandrel.

Other objects of the invention will be apparentas the description proceeds and when taken in conjunction with the accompanying drawing, wherein:

Figure 1 is an elevation of strip material coiled into helical convolutions in accordance with the present invention;

Figure 2 is a diagrammatic side elevation of a tool and work piece, partly in section;

ent sizes in accordance with .the size of the cylindrical support selected. In winding the strip material about the cylindrical support, it is wound tightly and without substantial space between adjacent convolutions. This material or rat-tail thus may be used for reaming small Figure 3 is a fragmentary side elevation of a somewhat modified tool;

Figure 4 is a diagrammatic view illustrating the coiled strip formed into an endless rope and mounted on driving pulleys; and

Figure 5 is a diagrammatic view illustrating a somewhat modified .tool with parts broken away.

According to the present invention, helically coiled abrasive strip material is provided, as shown at it in Figure 1, which has a permanent set imparted thereto tending to retain the strip material in its coiled form. The strip material may be conveniently manufactured by cutting ordinary abrasive-coated cloth or paper into narrow strips and ribbons. Abrasive material of this type is formed by adhering abrasive grains to paper, cloth or the like, and the adhesive, besides bonding the abrasive to the backing material, also imparts body to the material and some-= what stifiens the material, although leaving it still quite flexible. The adhesive may be of many types, but satisfactory results are obtained whenv an animal hide glue is employed. While in some cases satisfactory results will be obtained by employing a paper backing, it is preferred in all cases, and is esential in some cases, that a woven fabric backing should be employed. Excellent is then steamed and is thereafter allowed to cool and dry before removal from a cylindrical support. The steaming operation softens the adhesive and when the adhesive again sets upon subsequent drying and cooling, a permanent set is imparted to the strip material. The cylindrical support may be removed longitudinally of the coil without uncolling the strip material, thus rat-tail having helical convolutions. The rope holes extending completely through an article. For example, the operator merely forces one end of the rope or rat-tail through the hole, grasping it by both ends and reciprocating it back and forth in the hole. As thus used, ,the article is particularly eflective in removing burrs at the edges of the hole, although it effects a satisfactory finishingoperation at the interior of the work piece. By manipulation of .the coiled strip material its effective diameter, when in tightly coiled condition, may be controlled within substantial limits. Thus by applying greater tension to the coil while twisting it to maintain adjacent convolutions in contact, the diameter may be varied while at the same time a fairly rigid relationship is maintained. I

Instead of employ the coil, rope, or rat'- tail as just described, it may be used in combination with a supporting mandrel. Thus as shown in Figure 2, a mandrel 20 is provided having aslot 2! at its lower end. As seen in this figure, the mandrel 2e issupported in a suitable chuck 22 which may be provided on a drill press or the like. In this figure a work piece is shown at 28 having a blind hole 24 therein to be reamed. A coil of strip material 25 is positioned over the mandrel and the lower end thereof is entered into the slot 2!. In positioning the strip material over the mandrel the coil may be simply slightly loosened or uncoiled so as to slip freely over the mandrel until the lower end thereof is adjacent the slot 2|. Attention of course must be given to the proper end of the coil with respect to rotation of the mandrel so that rotation of the mandrel 20 within the hole 24 will tend to tighten the strip material 25 on the mandrel.

This arrangement provides for the ready assembly of strip material with a supporting mandrel in a manner such that in use it tends to tighten firmly on the mandrel, and will thus prevent inadvertent slippage. In addition, the provision of the strip material in this form avoids overlaps of double thickness which would result in providing a tool which was not of strictly circular cross section. Furthermore, by arranging the strip material in a helical formation on the mandrel with slight spaces adjacent convolutions as indicated at 25, the spaces between adjacent convolutions may receive grit and metal particles; and due to the helical convolutions, the tool thus formed will be self-clearing.

In the event that the hole to be reamed is as close as possible to the bottom, it will normally be desirable to provide a mandrel which is cylindrical from end to end. In other cases, however, it may be preferable to provide a mandrel which is slightly tapered. The mandrel in Figure 3 is tapered adjacent its lower end as indicated at 3|. A slot 32 is provided for the reception of an end of the strip material 33, which is assembled thereon in the same manner as on the mandrel 20 shown in Figure 2. By providing a tapered lower end on the mandrel, provision is made for gradual engagement between the abrasive coated surface of the strip material and the interior surface of the hole to be reamed, thus facilitating introduction of the tool into the hole.

The improved article of manufacture may also be employed in an entirely different manner, as is illustrated in Figure 4. In this figure is shown a pair of pulleys and 4|, and the strip material is formed into an endless belt 42 by joining together opposite ends of a single continuous rope or rat-tail of the coil material. Pulleys 40 and 4| have grooves which receive the rope thus formed. Preferably the strip material is coiled sufiiciently tightly so that on a straight run of the material, adjacent convolutions are in contact. This, however, is not strictly necessary and the convolutions may be slightly spaced as indicated in Figure 1.

The set-up illustrated in Figure 4 has many uses, as for example in finishing ring slots in pistons, and particularly for removing burrs from the corners of such slots.

In Figure 5 we have illustrated a specifically different form of tool which has certain advantages over those previously described. In this case the tool comprises a core of rubber on which is wound a narrow strip of flexible abrasive material. In this figure the core is indicated generally at and comprises an inner helically wound strip of rubber 5|. Over this and in engagement with it iswound a second strip of rubber 52, the second strip being wound oppositely to the first strip so that the convolutions of the strips 5| and 52 cross. This core may conveniently be made by winding the strips as shown onto a cylindrical or tapered mandrel. The crossing convolutions of strips 5| and 52 are secured together where they cross 'as by suitable rubber cement or the like. Over this core is wound a cover of flexible abrasive material 53. The flexible abrasive strip 53 is wound oppositely and a cover of a helically wound flexible abrasive to the strip 52 which it engages so that the convolutions of the strip 53 cross convolutions of the outer rubber strip 52. The abrasive strip 53 is tacked, as by suitable adhesive, at several points to the outer surface of the rubber strip 52.

The strips 5| and 52 are of a good quality of highly resilient rubber, and of a width and thickness selected to impart the requisite strength and resilience to the completed article.

This article may be advantageously used in sanding-out holes, and will provide a certain amount of internal expansion pressure after the device has been inserted into the hole. As a result, an operation more closely resembling honing may be effected.

In Figures 2 to 5 are illustrated a few of the many uses to which the improved article of manufacture may be adapted. Many others will suggest themselves to those skilled in the art.

While the basic article of manufacture and method of production has been fully described. and preferred uses of this article of manufacture are illustrated and described, it will be appreciated that this has been done solely to enable those skilled in the art to practice the invention, the scope of which is indicated by the appended claims.

What we claim as our invention is:

1. An abrasive tool comprising a hollow core of two oppositely wound, helical rubber strips strip.

2. An abrasive tool comprising a hollow core of two oppositely wound, helical rubber strips, the convolutions of said strips being secured together where they cross, and a cover of a helically wound flexible abrasive strip secured to said core.

3. An abrasive article comprising an endless tubular helix formed from a single flexible strip of abrasive material having a permanent set imparted thereto.

4. An abrasive article comprising an endless tubular helix formed from a single flexible strip of abrasive material having a permanent set imparted thereto, adjacent convolutions of the helix being in contact with each other.

5. An abrasive article having a core of resilient material and a cover of abrasive material, said core comprising two oppositely wound strips arranged one within the other and secured together, the cover being wound upon and secured to the outermost strip aforesaid.

6. An abrasive article having a core, and a cover therefor, said core comprising two oppositely wound helical strips of resilient material, the convolutions of said strips being secured together where they cross, the cover being a helically wound flexible abrasive strip secured to said core.

'7. An abrasive article comprising an endless tubular helix of abrasive material having a per manent set imparted thereto.

8. An abrasive article comprising an endless tubular helix of abrasive material having a permanent set imparted thereto, adjacent convolutions of the helix being spaced slightly apart throughout the length of said helix.

9. An abrasive article having a core, and a cover therefor, said core comprising two oppositely wound helical strips of resilient material, the cover being a helically wound flexible abrasive strip.

10. An abrasive article having a core and a terial, the outermost strip being formed of abrasive material.

12. An abrasive article having two oppositely wound helical strips, both being flexible, the convolutions of one strip being secured to the convolutions of the other strip, the outermost strip having an outer surface of abrasive material.

13. An abrasive article comprising abrasive strip material coiled into helical convolutions and having a permanent set imparted thereto tending to retain the strip material in its coiled form, spaces being provided between adjacent convolutions of the coiled strip material for the reception of grit and metal particles, said strip material comprising a relatively narrow strip of abrasively coated sheet material.

WILLIAM S. HOSKIN.

FRANK B. WOLFSCHLAGER. 

